This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. This is R01-funded double-blind, prospective, randomized trial assessing the molecular and cellular effects of tea treatment on oral cells in smokers (>20 cigarettes/day) and non smokers. The treatments are: green tea (400 mg of tea powder per cup), black tea, caffeinated water, and water (placebo). There is a 3-week run in period, a 4-week treatment period, and a 2-week washout period. The subjects will drink and swallow the materials in a prescribed specific manner;a total of 5 cups/day will be consumed. The PI is extremely experienced in this area. The cellular studies to be performed are varied. Oral keratinocytes will be examined for: pleomorphism, hyperchromatism, binucleation, analysis of DNA, enals and GSH, RT-PCR for enzyme expression, and protein and RNA isolation. Urine will be studied by HPLC for tea polyphenols and blood DNA will be analyzed. Apoptosis will be studied. Page 12 of the protocol indicates the studies to be performed but it is extremely cursory without a specific description of each assay, it's use, and possible interferences or problems.